Asked how close a new contract was after helping Ferrari to secure a one-two finish at the Bahrain Grand Prix, Sainz replied: “I think we are close. Very close. Very, very close. Extremely close. Nearly there.”
Ferrari team principal Mattia Binotto confirmed the deal has already been verbally agreed.
“I think we found an agreement,” he added. “It’s only a matter to translate it into paper.”
Sainz joined Ferrari from McLaren for the 2021 season on a two-year contract, which is due to expire at the end of the current campaign.
Talks over an extension for Sainz have been taking place throughout the winter and it now appears ready to be formally signed off.
The Spaniard took second place behind teammate Charles Leclerc in the season-opener in Bahrain, scoring his fifth podium finish for Ferrari.
Sainz, who finished ahead of Leclerc in the championship during his first season at the Maranello-based team, admitted he had a difficult weekend in Bahrain.
“For me it’s been a very tricky weekend, I’m not going to lie,” Sainz said after Sunday’s race.
“I didn’t have the pace today. But I managed to hold in there and bring the one-two for the team.
“I have some homework to do over these next few days and I’m sure I will come back stronger.”
But Sainz was delighted by Ferrari’s resurgent start to F1’s new era and declared the Italian outfit is “properly back” and ready to challenge for world titles again.
“I’m particularly happy for the whole team,” he said.
“It’s massive, you know, after two difficult years to be back and be on a one-two, it shows that all the hard work has just paid off and that we are back in the fight, back to where Ferrari should be.
“Congratulations to Charles because I think he drove a really good race. And he’s been on it the whole weekend.
“So to bring home this one-two means a lot to all of us and to all the tifosi and for sure today, we need to celebrate because it’s a huge day.”